The invention relates to control apparatus wherein cam elements are selectively movable on rotational displacement of a shaft to contact fixed actuation elements, contact between the cam elements and the actuation elements causing specific work functions to occur. In particular, a single control handle is arranged to control the rotational displacement of at least two shaft elements arranged in a mutually perpendicular relationship, each of the cam elements being fixed to one of the shaft elements and thereby being displaced on rotation of said shaft elements. Selective displacement of the cam elements causes said elements to contact fixed actuation structures, such as well-known roller switches, to activate said structures. The actuation structures interface with devices such as motors, etc. to operate said devices. A common useage of the present invention is as a control mechanism for operating tow multiple-speed electric motors either separately or simultaneously in any combination of speeds through the use of a single control handle. The control handle is capable of alternately displacing each of the shaft elements to position the cam elements carried on said shaft elements in a predetermined fashion, movement of the cam elements to these predetermined positions acting to bias switch elements or the like into active positions. Switch elements of a well-known type having friction rollers which activate electrical circuits on rotational displacement of the rollers can be conveniently employed in the practice of the invention.
The present control mechanism exhibits a variety of functional capabilities, one of the more useful of which is the ability to operate two motive devices, such as multiple-speed motors, with one hand from one control station. The present invention provides this capability due to the structural provision whereby at least two shaft elements can be rotationally displaced by one control handle. Thus, an operator of the invention need use only one hand to control at least two motors either separately or simultaneously throughout the full range of speeds of each of the motors. The cam elements carried on the aforementioned shaft elements can be configurated in a variety of ways depending on operational requirements. For example, previously activated actuation or switch elements can be maintained in an active position when a successive actuation element is activated or, alternatively, as succeeding actuation elements are activated, previously activated actuation elements can be inactivated. As can clearly be seen, any desired combination of the foregoing capabilities can be accomplished through simple modification of the camming surfaces of the cam elements. It is also believed to be apparent from the teachings of the invention that any desired number of cam elements can be carried on the shaft elements to correspond to and control the multiple operations of which the motive devices being controlled are capable.
It is therefore an object of the invention to provide a control mechanism capable of operating at least two multiple-operation motive devices, such as multiple-speed motors, either separately or simultaneously in any combination of operation thereof.
It is another object of the invention to provide a control mechanism operable by means of a single control handle, such as of the "joy stick" type, whereby at least two multiple-operation motive devices can be either separately or simultaneously controlled throughout the full range of operational combination of which said motive devices are capable.
Further objects and advantages of the invention can be understood and appreciated in light of the following detailed description of the preferred embodiment of the invention.